Table 1.

NIST 1 °C/division Mercury LiG Thermometer Calibration Resolution Limits (±2σ, °C).

	Eye Alone	Magnifying Lens
accuracy limit (resolution) a	0.300	0.114
visual repeatability	0.144	0.144
per-measurement uncertainty b	0.326	0.178
anomaly uncertainty c	0.461	0.252

^a Three significant figures are used throughout to reduce round-off error. ^b root–sum–square of resolution and visual repeatability. ^c Uncertainty in an anomaly is the root–sum–square of the uncertainties in the differenced magnitudes.